Final answer:
To display a date in the custom format 'Nov, 2019', you must choose the custom format option and enter a format code like 'mmm, yyyy' in the program's format settings. Therefore, the correct option is 1).
Step-by-step explanation:
To display a date in a custom format such as "Nov, 2019", you would need to select a custom format option within your spreadsheet or word processing software. Default formats, standard formats, and system formats typically refer to the pre-defined date formats that are built into the program. Since these pre-set options do not include the specific format you described, customizing the date format is required.
To create a custom date format, you would usually go into the format settings of the program you are using and specify how you want the date components to appear. For instance, in Microsoft Excel, you would right-click on the cell, choose 'Format Cells', navigate to the 'Custom' category, and enter a code such as 'mmm, yyyy' to achieve the desired format.
This approach will give you the flexibility to display dates in virtually any format you wish, beyond what is made available by the software's standard options.
Therefore, the correct option is 1).